Depends on budget and hp.Easiest is nc mx5 5 or 6 speed. Bolts straight up as they came out of the factory with them.The gearbox sits at a 10degree angle to the motor though. So either you mount the engine on a angle as per mx5 using custom mounts or the gear stick will be canted over to the pasenger side 10 degrees. You can just bend the gear stick back though. 5 speed was not available in aus but you may be able to import one.T5 out of falcon/commodore can be adapted to fit using abellhousing out of the US.T9 can be used. There a plenty of companies who make bellhousings for them in the uk. Getting expensive for what they are and dont hold much power.W50 or W55 w58 toyota boxes can be used. Dellow do a bellhousing.S5 rx7 box is a good option. Roger caroll in sa does a bellhousing. Though good gearboxes and parts for them are thin in the ground and as such are pricey to reco.